In fuse assemblies with conventional construction, a fusible element is stretched diagonally between the ends of a tubular member such as a cartridge, and the ends of the fusible elements are soldered at both ends of the tube which is capped with a ferrule or a similar means. In the construction of some fuse assemblies, the ends of the fusible element are bent over the outside surface of the tube before capping the ends with the ferrule, metal cap or the like. This construction requires that a suitable gap be provided between the ferrule (or cap) and the ends of the tube. Fuse assemblies with such construction, however, have several drawbacks. Thus, if a fuse element with a relatively large cross sectional area is used, it becomes difficult to fit the ferrule or the cap at the ends of the tube. On the other hand, if the cross sectional area of the fuse is relatively small, the ferrule or cap will have a tendency to be displaced eccentrically relative to the axis of the tube. Additionally, an inclination of the cap will result from this arrangement making it difficult to install the fuse assembly into a fuse-holder. Moreover, the fusible element will be subjected to compression between the ends of the tube and the inside surface of the caps thereby resulting in deformation of the fusible element and/or its rupture.
In some conventional fuses, there is also a large clearance between the ends of the tube and the inside of the end caps or ferrules. This generally results in poor electrical connection and inferior performance.
In U.S. Pat. No. 3,094,600 which issued to Frederick J. Kozacka on June 18, 1963, an improved cartridge fuse is disclosed which comprises solder joints between the caps or ferrules and the ends of fusible element wherein the solder joints are situated inside of the fuse. As shown more specifically in FIGS. 3 and 4 of Kozacka, the solidified solder pool has projections 5a, 5a which extend in a direction longitudinally of casing 2 into gaps G formed between casing 2 and the end caps 6,6. Col. 2, ls 43-46. This construction, however, does not overcome the difficulties and disadvantages hereinbefore discussed connection with the prior art fuses.
Accordingly, it is an object of this invention to provide an improved fuse assembly.
It is a further object of this invention to provide a fuse assembly which, due to its novel and unique construction, is free from the foregoing disadvantages and limitations.
It is another object of this invention to provide a fuse assembly comprising fuse elements of large or small cross sectional areas without displacement or difficulty in installation.
It is still another object of this invention to provide a fuse assembly with such improved construction without adversely effecting its performance characteristic or breaking capacity.
The foregoing and other objects of this invention will be more fully described in the following detailed description of the invention taken in conjunction with the accompanying drawings.